The obvious place would have been to slip it behind the LCD screen, but the LCD has a metal cover on the rear so I don't think it would work.
You may however be able to get a small NFC sticker and put it between the LCD and the front of the watch (in the area left where the LCD is off-centre)?
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
It could be worth a try!
The obvious place would have been to slip it behind the LCD screen, but the LCD has a metal cover on the rear so I don't think it would work.
You may however be able to get a small NFC sticker and put it between the LCD and the front of the watch (in the area left where the LCD is off-centre)?